Would it be possible to also clarify the situation with scala 2.12? If Flink 1.3 cannot be built with 2.12 it would better to say so directly. This is rather vague:
"Newer versions may be compatible, depending on breaking changes in the language
features used by Flink, and the availability of Flink’s dependencies in those Scala versions.
The dependencies written in Scala include for example Kafka, Akka, Scalatest, and scopt."